Adducts of certain unsaturated olefinic or acetylenic halides with hexamethylenetetramine are effective germicides when present in concentrations as low as 0.01 percent in water-containing organic mixtures such as, for example, emulsified cutting oils, latexes, latex paints, aqueous adhesives, hydraulic fluids and pulp dispersions used in paper-making. The adducts, the mode of their preparation, and their utility are taught in U.S. Pat. No. 3,228,829.
In particular, as disclosed in U.S. Pat. No. 3,228,829, adducts formed by the reaction of hexamethylenetetramine with an olefinically or acetylenically unsaturated bromide, chloride, or iodide wherein the halide molecule contains a maximum of about eight carbon atoms, exhibit the antimicrobial activity of the unsaturated halide moiety as well as other valuable properties not exhibited by the unsaturated halide.
Unsaturated halohydrocarbons which form adducts with hexamethylenetetramine having particularly high antimicrobial activity are dihaloalkenes and haloalkynes such as propargyl bromide, propargyl chloride, 1,3-dichloropropene, 2,3-dichloropropene, diiodoacetylene and 1,4-dichloro-2-butyne.
The hexamethylenetetramine:unsaturated aliphatic halide adducts are prepared easily by mixing together the proper amounts of the two reactants in a suitable solvent at or about room temperature. Solvents mentioned in the literature as suitable for use in this general reaction include, for example, dichloromethane, chloroform, methanol and ethanol.
Although, as set forth hereinbefore, these adducts are very effective antimicrobials, under certain conditions it has been found that the compounds may undergo spontaneous exothermic decomposition. This phenomenon, if it occurs, has arisen usually in those instances where the mass of a substantially water-free adduct is such that there is inadequate means for heat transfer from the interior of the mass to the surrounding environment. Generally, such sporadic spontaneous decomposition has been found to occur where packages or large compact piles of the substantially water-free compound have been stored or accumulated, such as commonly practiced in the warehousing or other inventory storage of materials. Heretofore, means for providing heat transfer to eliminate or suppress the decomposition primarily have been directed to limiting the size of the mass of the substantially water-free biocidal adduct in at least one dimension to provide a short heat transfer path which prevents the development of a detrimentally large temperature difference between the interior of the mass and tht environment, e.g., the atmosphere and walls of a package. Conveniently, small or thin elongated shaped packages wherein large substantially water-free masses are not accumulated in a given location are suitable for storage.
Now, unexpectedly, I have found a substantially water-free composition comprising an adduct of hexamethylenetetramine with an olefinic or acetylenic halide wherein autodecomposition from spontaneous exothermic reaction is entirely prevented or suppressed to a point where there is no detrimental product degradation.
It is a principal object of the present invention to provide a substantially water-free composition comprising an adduct of hexamethylenetetramine with an olefinic or acetylenic halide which does not undergo spontaneous detrimental degradation when stored in large masses.
It is another object of the present invention to provide a substantially water-free composition wherein spontaneous exothermic decomposition of adducts of the type set forth hereinbefore can be suppressed and even eliminated, thus markedly increasing the ease of bulk storage and packaging of such adducts.
It is a further object of the present invention to provide a substantially water-free composition which is stable against autoinitiated exothermic reaction of the active antimicrobial ingredient, i.e., a 1:1 hexamethylenetetramine:unsaturated aliphatic halide adduct, but wherein the biocidal effectiveness of this active ingredient is not impaired.
It is also an object of the present invention to provide a substantially water-free composition in which such an exothermic degradation will not be self-propagating throughout a compact mass.
These and other objects and advantages readily will become apparent from the detailed description presented hereinafter.